DUBUS

DUBUS is the international bilingual, english and german, written magazine for Ham-Radio on VHF/UHF and Microwaves. The magazine is published quarterly in March, June, September and December. Each issue of over 100 pages, in A5, is devoted to a mix of state-of-the-art technical articles and DX operating news. National DUBUS representatives are in Austria, Australia, Belgium, Bulgaria, Canada, Czech Rep., Denmark, Eire, France, Finland, Greece, Italy, Japan, Netherlands, New Zealand, Norway, Portugal, Poland, Romania, Russia, Rep. of South Africa, Slovenia, Spain, Sweden, Switzerland, Ukraine, United Kingdom, USA.

DUBUS 3-2024 Vol-53

Editorial.
A High Efficiency Solid State kW amplifier for the 2m band with Planar Baluns
by Sylvain Klingebiel, F6CIS, and Michel Bourdon, F6DZK
A high-efficiency 144 MHz LDMOS 1kW PA using printed planar baluns has been designed with the aim to reduce the power dissipated by the LDMOS transistors as much as possible and thus increase reliability. These planar baluns also make the construction of tge SSPA simpler and more reproducible. The drain currents can be measured separately which makes it possible to check that the push-pull is correctly balanced and that maximum drain current is not exceeded ... [Printed baluns | Thermal characterization | Optimizing efficiency | Circuit diagram | PCB | Measurement results].
Phase Noise Measurement Revisited: Revisited
by Dennis G. Sweeney, WA4LPR, and Jim Davey, K8RZ
The phase noise measurement paper Phase Noise Measurement Revisited recently published in DUBUS suggested that high performance computer sound cards matched with the appropriate software might be used to measure phase noise. At the time of publication, suitable software had not been found. As a result of the DUBUS publication, Harke Smits PA0HRK suggested using the Focusrite Scarlett Solo sound card with DG8SAQ's AudioMeter software to do phase noise measurement. This paper outlines our efforts to use Focusrite sound card and AudioMeter to do phase noise measurement ... [Sound card interface | Software | Analysis and configuration | Measurement].
Aircraft Scatter: New perspectives, questionable concepts (part 2)
by Nils Schiffhauser, DK8OK
Is it possible to track the path of aircraft using WSPR log data? And how can this be proven or why is this practically impossible? In the concluding second part, Nils Schiffhauser, DK8OK, concentrates on Doppler traces and their levels ... [Doppler, like a fingerprint | Identify curves | Distance role | Examples].
241-250 GHz Transverter. The Top Band (1mm) is within reach
by Andrew Anderson, VK3CV/WQ1S
In this article I describe a new approch to getting on the top amateur radio allocated band at 241-250 GHz without the use of high order external multiplier chains and passive mixers. The approach is based on a newly released chip, the TRA-240-091 from Indie Semiconductor (formerly Silicon Radar). The chip covers the entire amateur primary and secondary allocations in the 1mm band from 241-250 GHz. The chip will actually cover 222.5-267.5 GHz ... [Circuit diagram | Circuit theory of operation | Software operation | PLL configuration | PCB construction | Testing and optimization].
Q65-15C on Auroral Es Backscatter and other Auroral Propagation
by Rex Moncur, VK7MO, and Brodie Churchill, VK3MAP, and Dr Andrew Klekociuk
Over the past 18 months we have been conducting test on Auroral Scatter with Q65-15C that have produced over 4000 decodes mainly between VK7MO and VK3MAP. The sensitivity of Q65-15C with its ability to measure Doppler and signal levels and record files has proved to be very useful for not only QSOs but also for identifying the characteristics of various type of propagation ... [Aurora Es forward-scatter | Aurora Es back-scatter | Setting for reception].
Aurora News.
Tropo Reports.
Microwave North America.
Microwave Japan.
Microwave Europe.
Microwave Spain and Portugal.
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